Comparing oral health care utilization estimates in the United States across three nationally representative surveys

Health Services Research, April, 2002 by Mark D. Macek, Richard J. Manski, Clemencia M. Vargas, John F. Moeller

Utilization Estimates Across Surveys

Table 4 compares the 1993 NHIS age-standardized overall dental estimate for adults with estimates from the NHANES III and MEPS data instruments. Dental visit estimates derived from the NHANES III and MEPS instruments were significantly different from those derived from the 1993 NHIS. For example, NHANES IIIa and MEPS substantially underestimated the 1993 NHIS estimate by 17 and 30 percent, respectively. Although estimates from the 1993 NHIS and NHANES IIIb were nearer, NHANES still overestimated the 1993 NHIS estimate by approximately 5 percent.

Utilization Estimate Trends Across Surveys

Table 5 lists stratum-specific dental visit odds ratio associations for the 1993 NHIS, NHANES IIa and NHANES IIIb, and MEPS. With the exception of age, stratum-specific associations were consistent across surveys. For example, regardless of the data source, men were always significantly less likely than women. Non-Hispanic Whites were always significantly more likely than Hispanics, and persons with higher socioeconomic status (measured via poverty status and level of education) were always significantly more likely than those with low socioeconomic status to have had a dental visit in the last year. Age-specific odds ratio associations were not consistent across surveys, however. MEPS was the only data instrument showing that younger adults were significantly less likely than older adults to have had a dental visit in the last year.

DISCUSSION

To date, several epidemiological investigations of oral health care utilization have been conducted in the United States, including a recent telephone survey conducted by the American Dental Association and Gallup Organization, Incorporated (American Dental Association 1998) of adult attitudes and behaviors. We only included the nationally representative NHIS, NHANES, and health expenditure surveys in this investigation, however, because these surveys used a common sampling frame. We limited the investigation to surveys with a common sampling frame so that differences in the target samples would not impact the variations noted across surveys.

This investigation showed that there was a substantial and statistically significant difference between the overall dental visit estimates derived from the standard NHIS and estimates derived from NHANES and the health expenditure surveys. The investigation also showed that despite differences in the overall estimates, relative stratum-specific dental visit associations were consistent across surveys. The consistent trends were comforting, as a policymaker who was interested, for example, in determining whether non-Hispanic Whites were more likely to report a dental visit than non-Hispanic Blacks would find identical associations, regardless of the data source used. What is disconcerting, however, is that a researcher or policymaker who used the NI-US to estimate the overall proportion of the U.S. population with a dental visit would have drawn a vastly different conclusion about utilization than the researcher or policymaker who used NHANES or the health expenditure surveys, and this difference could have had a substantial impact on program planning, estimation of necessary funds, or determination of national personnel requirements. In the remainder of this section, we discuss some of the possible explanations for these discrepancies; relate the findings to study strengths and limitations; interpret the results in terms of relevant health policy, research, public health programs; and provide general recommendations for those who regularly rely on these data.